Buoyant safety paddle and method of manufacture thereof

ABSTRACT

A buoyant safety paddle ( 11 ) for a kayak, a canoe or other small boat facilitates kayak deep-water self-rescue reentries and facilitates the movement of small boats over aqueous surfaces. Such buoyant paddle displaces significant volume while minimizing weight eliminating the need for post-capsize attached flotation. Each such buoyant paddle&#39;s volume is predetermined and distributed to retain paddling efficiency. Each such buoyant paddle has a handle ( 19 ) which extends from one blade ( 12 ) or between two blades, and is water tight, with a continuous strong rigid skin ( 41 ) and low density core ( 42 ). This construction provides a buoyant, minimal weight, stiff, high strength paddle which is economical to manufacture.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

(Not Applicable)

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to flotation devices for self-rescue from a capsized kayak, and to paddles or oars for manually propelling and maneuvering kayaks, canoes or other small boats.

BACKGROUND OF THE INVENTION

2. Description of the Prior Art

Paddles and oars have evolved over thousands of years and the most popular material for manufacture had long been wood. During the 20th Century new materials were introduced. U.S. Pat. No. 738,053 to Murdock (1903) and U.S. Pat. No. 2,527,040 to Swenson (1950) incorporated using hollow metal oars. In 1977, U.S. Pat. No. 4,061,106 to Ware elaborated on the importance of fiber placement in building light, strong racing paddles. U.S. Pat. No. 4,303,402 to Gooding (1981) and U.S. Pat. No. 6,991,501 to Wilce (2006) championed attaining low weight using combinations of plastic and aluminum. U.S. Pat. No. 5,820,424 to Steinhour and Addison (1998) purported that lightweight kayak paddles with bent shafts are more ergonomic and can be oriented by touch alone.

Regardless of construction materials and method, contemporary practice provides only just enough buoyancy to float the paddle. Paddle manufacturing and paddle patents have focused on use of the paddle as a means of manually propelling and maneuvering kayaks, paddle weight, and on economy of production.

Small differences in weight can be of considerable significance during the use of paddles. The paddle must be repeatedly manipulated, often thousands of times during each use, and weight has a cumulative effect on the effort that is demanded of the user of the paddle. The current practice is to minimize weight by any method including reducing volume.

It is also well known in the art that rigid skin on low-density core construction is strong, rigid and durable. Surfboard, sailboard and racing yacht manufacturers use construction employing a low-density core material sandwiched between strong, thin facings. The result is a lightweight, strong, stiff composite structure which acts in the same manner as a continuous beam with the skins taking bending stresses while the core acts as the “web” to carry shear and compressive loads. Surfboard manufacturers acquire roughly shaped closed-cell foam blanks, shape the blanks, and then cover the blank with a continuous skin of fiber reinforced plastic to create a surfboard.

The Greenland style paddle evolved over thousands of years. Many paddlers like the symmetry and claim it is a superior paddle for endurance and heavy weather. Greenland style paddles are predominantly carved from a single piece of wood and achieve minimal weight through wood selection and removing volume.

The European or modern style paddle emerged in the 20^(th) century. This is the most prevalent style. Blade area is concentrated far from the center of the paddle, increasing power. Blade shapes and paddle lengths have evolved to fill niches as they become popular. Sea kayaking paddles are at the long end of the length continuum and whitewater paddles are at the short end. Sea kayaking paddle blades are at the narrow end of the width continuum and whitewater paddle blades are at the wide end. Power faces can be flat, curved, spooned and/or have a dihedral from the center line. The paddle blades are generally asymmetric with the up side longer than the down side as a means of equalizing wet area on either side of the paddle's longitudinal axis at the apex of the stroke.

The European style paddle is constructed of various materials to meet weight, low rotational mass, propulsion efficiency, strength, durability, and price objectives. The least expensive, least capable paddles are normally fabricated with plastic blades and aluminum handles. The most expensive, most specialized performance paddles are usually fabricated with carbon fiber reinforced plastic.

Kayaking in rough waters carries with it the risk of capsizing. After a capsize in cold waters, life threatening issues of hypothermia or drowning are of immediate concern. Methods exist for righting and reentering overturned kayaks. Skilled kayakers frequently execute a kayak roll to “right” an inverted kayak. If the capsize leads to egress from the cockpit, the skilled paddler may reenter the cockpit upside down and underwater before executing the roll. However, rough seas, skill level, strength, and hypothermia sometimes combine to make it impossible to successfully complete such a skilled maneuver. Accordingly, there exists in the prior art several devices to assist kayakers in righting and/or reentering capsized kayaks

Among such devices, U.S. Pat. No. 5,279,248 to Blachford and Alistari M. (1994) describes a device having a rapidly self-inflating means for flotation with a minimum volume of one cubic foot of gas. It is adapted for positioning to one side of the kayak, spaced from the kayak for movement in an arc of at least 90 degrees about the kayak by means of force applied to the handle of the device. After capsize, the handle of the flotation device is grasped and the device inflated. Force is then applied to the handle to rotate the kayak and paddler to an upright position. This kayak righting apparatus is a separate piece of equipment to maintain and stow. After capsize such kayak righting apparatus must be located, inflated and used as a source of buoyancy to right the kayak. This procedure requires skill and removing at least one hand from the paddle. Rolling the kayak upright must wait for automatic inflation to provided adequate buoyancy. After the kayak is righted such kayak righting apparatus needs to be deflated and stored to get the paddle and the kayak back under control. Once self inflating cartridges are spent, utility is gone as it is impossible to orally inflate after capsizing, with the paddler's head underwater.

It is well known in the art to use a post-capsize attached flotation device to assist in self-rescue or solo reentry into a capsized kayak. The most commonly used device is an inflatable or foam sheath, jacket, collar or cuff. The sheath fits over one of the kayak paddle blades so that one end of the paddle becomes significantly buoyant. The paddle may then be deployed as an outrigger to assist in the self-rescue effort.

Contemporary inflatable flotation devices comprise an envelope having an internal cavity or sleeve that fits over the kayak paddle blade. The technique for using this kind of post-capsize attached flotation device in kayak deep-water self-rescue typically involves the following steps:

-   -   (1) turning the capsized kayak into the upright position and         hanging onto the kayak;     -   (2) selecting a side for reentry and taking a position beside         the cockpit     -   (3) finding and removing post-capsize attached flotation device         from its storage place;     -   (4) attaching a post-capsize attached flotation device to one         blade;     -   (5) inflating the flotation device until it is secure on the         blade and sufficiently full to provide buoyancy;     -   (6) slipping other paddle blade under rear deck rigging at a         right angle to the gunwale, with the inflated flotation device         extended as an outrigger;     -   (7) kicking the legs to the water surface and simultaneously         pulling with both arms to squirm up on rear deck,     -   (8) sliding stomach down, head to stern until feet can slip into         cockpit;     -   (9) twisting over to slide feet into cockpit;     -   (10) lowering butt onto seat;     -   (11) slipping paddle out from rear deck rigging;     -   (12) removing post-capsize attached flotation device;     -   (13) deflating post-capsize attached flotation device;     -   (14) stowing post-capsize attached flotation device;     -   (15) paddling to regain control of kayak.

The deep-water self-rescue reentry takes some dexterity and can be difficult in rough water. Difficulty increases as the time in cold water increases. Once righted the paddler still must deal with the unwieldiness of Paddling with a float on one blade. Usually the environment that created the need to do a reentry still exists after reentry, so it is important to get the kayak under control quickly.

Foam post-capsize attached flotation devices eliminate the inflation and deflation steps, but take up more storage space.

The added buoyancy of a post-capsize attached flotation can be helpful when learning to kayak roll. The float makes rolling easier allowing concentration on different parts of the roll without doing a wet exit. However, the kayak is difficult to maneuver with a float on one blade during the time between roll attempts.

Another method of kayak self-rescue is based on the post-capsize attached flotation's aid to rolling. This method is suitable for rough sea conditions when the kayak is inverted and requires that the kayaker have at least some understanding of and proficiency with reentry and roll techniques. It is significantly easier to execute than a kayak roll without a post-capsize attached flotation device. The technique includes the following steps:

-   -   (1) taking a position alongside the inverted kayak;     -   (2) placing the post-capsize attached flotation device onto the         paddle blade and inflating;     -   (3) taking a position beside the cockpit and facing stern;     -   (4) grasping the paddle handle along its length (with the         longer, float end toward the bow), and holding it against the         near coaming;     -   (5) reaching across the cockpit and grasping the opposite         coaming;     -   (6) taking a deep breath and quickly leaning back;     -   (7) employing a backward somersault, thrusting both legs into         the cockpit and taking a position securely inside, upside down         and underwater;     -   (8) positioning the paddle parallel to the kayak side in         preparation for a kayak roll;     -   (9) sweeping outwardly with the float end, then flicking hip and         pulling briskly downward so as to come to a full upright         position;

Brace strokes are used to prevent a kayak or canoe from capsizing. The paddle blade is slapped on the water or sculled through the water to generate force to keep the kayak upright. Success depends on sea conditions and kayaker skill. When the paddle blade angle is wrong, instead of providing lift it dives accelerating capsize. The leading edge of the blade must be held so it is always rising, creating lift. When the leading edge is diving it pulls the blade toward the bottom.

The present invention is directed to making paddling safer by overcoming one or more of the problems discussed above.

BRIEF SUMMARY OF THE INVENTION

The paddle combines the utility of a paddle with the utility of a post-capsize attached flotation device. This buoyant paddle for propelling and maneuvering a boat includes one or two blade(s) and a handle portion. This paddle has large displacement and minimal weight adding significant buoyancy to combine the function of such paddle and the function of a post-capsize attached flotation device. This paddle facilitates the movement of small boats over aqueous surfaces and is deployable as an outrigger to assist in deep-water self-rescue reentry to a capsized kayak. This invention relates to methods for manufacturing paddles with buoyancy, strength, efficiency, minimal weight, durability and economy.

Objects and Advantages

The goal of this buoyant paddle is to provide a safer paddle than is currently available, while maintaining acceptable paddling efficiency.

Accordingly, it is an object of this paddle to aid kayak reentry. When used in a deep-water kayak self-rescue reentry it eliminates six steps, reducing the reentry technique to these steps:

-   -   (1) turning the capsized kayak into the upright position and         hanging onto the kayak;     -   (2) selecting a side for reentry and taking a position beside         the cockpit     -   (3) slipping one blade under rear deck rigging at a right angle         to the gunwale, with the other blade extended as an outrigger;     -   (4) kicking the legs to the water surface and simultaneously         pulling with both arms to squirm up on rear deck,     -   (5) sliding stomach down, head to stern until feet are over         cockpit;     -   (6) twisting over to slide feet into cockpit;     -   (7) lowering butt onto seat;     -   (8) slipping paddle out from rear deck rigging;     -   (9) paddling to regain control of kayak.         A faster reentry is a safer reentry. Especially in cold water,         boaters need to minimize wet time.

Another object is to improve kayak roll reliability. The kayak roll is used to right an overturned kayak without doing a wet exit and a reentry. The invention's buoyancy is a built in flotation device always at the ready. Both clockwise and counter-clockwise rolls are assisted as buoyancy is built into both blades. A more reliable roll makes it less likely a kayaker will need to do a deep-water self-rescue reentry. A more reliable roll makes a safer kayaker. The built in flotation makes it easier to do reentry and roll recovery without needing to attach a float to the paddle or predetermine whether the roll will be clockwise or counter-clockwise.

A further object is to improve support stroke effectiveness. Brace strokes are used to prevent a kayak or canoe from capsizing. This buoyant paddle increases support provided by brace strokes and reduces the likelihood a paddle will dive on the brace stroke. Better brace strokes reduce the need for kayak rolling or deep-water self-rescue reentry. Better brace strokes make a safer kayaker.

A still further object is to provide a buoyant paddle of such construction and design so as to provide lightweight, low rotational mass, propulsion efficiency, strength, durability and economical manufacture. Lightweight, low rotational mass and propulsion efficiency can be safety issues when distance to safe harbor tests time and energy available. Strength and durability become safety issues if the primary paddle fails and the spare is less capable or missing. Economy becomes a safety factor if the price is beyond the means of the paddler.

The construction of this invention varies rigid skin thickness to increase strength where greatest torque will occur and to reduce rotational mass. The skin is thickest in the handle and thinnest in the fattest section of the blade.

Reduced rotational mass and buoyancy increase paddling efficiency. Reducing rotational mass puts more paddler energy into propelling the boat through the water by reducing the energy needed just to move the paddle. Increasing blade buoyancy lets the paddle pop out of the water at the end of the stroke reducing the energy absorbed by pulling the paddle up out of the water. The method of construction of this invention has the flexibility to produce paddle blade shapes tuned for efficiency in different applications and for different paddler preferences.

The method of construction of this invention has the flexibility to produce paddles for different price points. The rigid skin low density combination can be fabricated with various materials ranging from cheap to expensive. The rigid skin material pricing would increase from entry level polypropylene, through ABS (acrylonitrile butadiene styrene) and FRP (fiberglass reinforced plastic), to expensive carbon fiber/Kevlar reinforced plastic. The low density core material pricing would increase from free hollow, through EPS (expanded polystyrene) to expensive, rigid, tough, SAN (styreneacrylonitrile) or PVC (polyvinyl chloride) closed-cell foams.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a perspective view of the Greenland style embodiment of the invention.

FIG. 2 is a perspective view of the European style embodiment of the invention.

FIG. 3 is a perspective view of the canoe style embodiment of the invention.

FIG. 4 is a cross section of the handle portion of the paddle showing the rigid skin and low density core.

FIG. 5 is a cross section of the blade portion of the paddle showing the rigid skin and low density core.

FIG. 6 is a cross section along the longitudinal axis of the paddle showing the single continuous rigid skin encapsulating the low density core of the blades and the handle.

FIG. 7 is a cross section of the handle portion of a paddle fabricated by joining two rigid skin low density core halves along the longitudinal centerline of such paddle.

FIG. 8 is a perspective view of a modular paddle.

Reference Numerals in Drawings 11 Buoyant Safety Paddle 12 blade 13 major surface (blade face) 14 opposite major surface 15 side 16 opposite side 17 first end of blade 18 second end of blade 19 handle 41 rigid skin 42 low density core 81 four piece blade 1 82 four piece handle 1 83 four piece handle 2 84 four piece blade 2 85 three piece blade 1 86 three piece handle 87 three piece blade 2 88 two piece blade/handle 1 89 two piece blade/handle 2 91 extension

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1, 2, and 3 of the drawings, a paddle 11 in accordance with these embodiments of the invention have a paddle blade 12 with opposite facing major surfaces 13 and 14, and sides 15 and 16, extending between first and second ends 17 and 18 of the blade. A handle 19 extends from the first end 16 of the blade 12 to enable grasping and maneuvering of the paddle 11. The blade 12 may have any of the outlines that are customary in paddles for small watercraft such as canoes and kayaks. The handle portion 19 has a length that is dependent on the type of watercraft. Canoe paddles, for example, are proportioned to be gripped at the distal end by one hand of the user while the other hand grips the handle at a location which is relatively close to the blade 12. Kayak paddles are longer and have blades 12 at each end of the handle 19 which blades may be immersed in the water, alternately, at opposite sides of the hull of the kayak. The present invention is adaptable to paddles offerings of all differing types. The blade(s) 12 and handle 19 are encapsulated by a common rigid skin eliminating bulky, dense blade handle joints.

The blade 12 of these examples is thick enough to provide buoyancy. The dimensions of sides 15 and 16, in combination with dimensions of the paddle faces 13 and 14 are determined by buoyancy requirement. Increasing thickness increases volume. Increasing volume while minimizing weight increases buoyancy. The buoyancy required to perform a kayak reentry can vary with weather, kayak design, paddler physique and paddler skill level.

Referring to FIG. 1 of the drawings, a paddle in the Greenland style is symmetric with four power faces and a short rectangular handle between long blades. The Greenland style is the preferred embodiment of the buoyant safety paddle as in addition to symmetry and the short rectangular handle it has a better volume to skin ratio.

The symmetry of the Greenland style paddle lends itself to safety. The paddle can be held in any of four positions as all four faces are power faces. No matter how the buoyant safety paddle is grabbed, if the blade face is perpendicular to the water's surface paddling can start. The short rectangular handle allows a paddler to orient the buoyant safety paddle by touch alone. The combination of symmetry and short rectangular handle make it unnecessary to flip the paddle around its lateral axis or roll the paddle around its longitudinal axis to get the power face pulling. The combination of symmetry, short rectangular handle, and blade buoyancy encourages a powerful vertical stroke close to the side of the kayak. The rectangular handle provides good control of the paddle eliminating blade flutter and allowing efficient power strokes.

For a given paddle length and blade width a Greenland style buoyant safety paddle has more of its length in the fat cross section blade than in the narrow cross section of the handle. One inch, of 5 by 2 inch blade, has 14 square inches of skin and includes 10 cubic inches of volume for a volume-to-skin ratio of 1 to 0.71. Whereas 1 inch, of 1.5 by 1.2 inch handle, has 5.4 square inches of skin and includes 1.8 cubic inches of volume for a volume-to-skin ratio of just 1 to 0.33. Having less skin for a given volume means predetermined buoyancy can be achieved with a stronger, lighter paddle.

Referring to FIG. 2 of the drawings, a paddle in the European or modern style has blade area concentrated far from the center of the paddle handle. Such paddles' blades can be symmetric or asymmetric. Such paddles blades' Power faces can be flat, curved, spooned and/or have a dihedral from the center line.

Referring to FIG. 3 of the drawings, a canoe paddle is symmetric. The handle is generally “T” shaped.

Referring to FIGS. 4, 5, and 6 of the drawings, a paddle in accordance with these embodiments of the invention have a rigid skin 41 and a low density core 42. Such rigid skin and such low density core combine to provide paddle rigidity and strength. Such rigid skin and such low density core combine to provide increasing volume without a proportionate increase in weight. The present invention's buoyant paddles have more volume than common paddles while weighing approximately the same.

Referring to FIG. 7 of the drawings, a paddle in accordance with these embodiments of the invention has halves 71 and 72 joined with a longitudinal centerline seam 73. Such centerline seam can be a simple glue line or reinforced as means to increase rigidity and strength perpendicular to the power face.

Referring to FIG. 8 of the drawings, a paddle in accordance with these embodiments of the invention have a plurality of parts 81, 82, 83, 84, 85, 86, 87, 88, 89, and 91 that join together. The blade 81, handle 82, handle 83, and blade 84 join to form a four-piece paddle. The blade 85, handle 86, and blade 87 join to form a three-piece paddle. The blade/handle 88 and blade/handle 89 join to form a two-piece paddle. The extension 91 fits between handles 82 and 83 or between blade/handles 88 and 89 to increase the length of such four or such two-piece paddle. Each of said parts is constructed of a rigid skin over a low density core.

The rigid skin over low density core is manufactured by various methods. The most basic process involves carving a closed-cell foam blank, wrapping blank with fiberglass, wetting out with resin, curing, then finishing. A lighter stronger buoyant paddle can be produced by applying pressure with vacuum bagging to increase uniformity of resin saturation and to remove excess resin. The lightest and strongest buoyant paddle requires SAN closed-cell foam, carbon fiber fabric sleeves, heat-set epoxies, and heated presses. The foam is cut large, the carbon fiber sleeve is slipped over the core, the fiber is wetted out with epoxy, the wet paddle is slipped into the mold, pressure is applied squeezing the skin between mold and foam, and temperature is elevated to set the epoxy. Kevlar or other reinforcing fiber materials are used to add characteristics such as durability. Metal, polypropylene, or ABS rigid skins are made hollow and filled with pour foam to prevent buoyancy loss when rigid skin is punctured. After the two parts of the pour foam are mixed and poured, the foam expands and sets. To prevent paddle rupture, the pour foam parts are precisely measured and an escape route for excess foam is provided. 

1-16. (canceled)
 17. A buoyant paddle formed by (a) a rigid continuous seamless skin over (b) a low density or hollow core shape with (c) thick paddle blade(s) and (d) a handle to attain (e) a weight to volume ratio which provides a minimum 15.5 pounds of inherent buoyancy, whereby a human can do a deep-water self-rescue reentry and efficiently propel a small boat.
 18. The combination of claim 17 wherein said seamless skin is formed at least in part of plastic reinforced with fiber such as fiberglass, carbon fiber, or Kevlar.
 19. The combination of claim 17 wherein said seamless skin is formed at least in part of un-reinforced plastic such as polypropylene or ABS (acrylonitrile butadiene styrene).
 20. The combination of claim 17 wherein thickness of said seamless skin is varied in proportion to stress loads, thick in the loom where strength is needed most and thin in the blade where loads are less and cross section is greater, whereby improving strength/weight ratio over uniformly thick skin.
 21. The combination of claim 17 wherein said core is hollow.
 22. The combination of claim 17 wherein said core is low density closed-cell foam.
 23. The combination of claim 17 wherein the paddle's two blade shape is (a) symmetric, similar to a Greenland paddle, and (b) has wide blades a minimum of 1.5 inches thick.
 24. The combination of claim 17 wherein the paddle's two blade shape is (a) asymmetric, similar to a European or modern paddle, and (b) has blades a minimum of 1.5 inches thick.
 25. The combination of claim 17 wherein the single blade shape is (a) similar to a canoe paddle shape and (b) has blades a minimum of 1.5 inches thick.
 26. The combination of claim 17 wherein the paddle is manufactured as a single continuous seamless rigid skin over a low density core as means to eliminate joints between blade faces and between handle and blade.
 27. In a paddle for propelling and maneuvering a small boat, the combination comprising: (a) one or two paddle blades and handle (b) a continuous seamless rigid skin and a low density core (c) a volume to weight ratio which provides the buoyancy of a Class III PFD, whereby the safer paddle facilitates self-rescue, rolling and bracing without compromising paddling efficiency.
 28. In a method of manufacturing a paddle for use with a small boat, the steps comprising: forming a closedcell foam blank, wrapping said blank completely with a seamless reinforcing fabric sleeve, wetting out the fabric with resin, curing, then finishing. 